Codeine is an opioid analgesic and antitussive medication used to treat mild to moderate pain and relieve coughs. It works by binding to opioid receptors in the brain to reduce the perception of pain and by suppressing the cough reflex in the medulla. It is often combined with paracetamol to provide greater pain relief.

Tramadol is a centrally acting synthetic opioid analgesic used to treat moderate to moderately severe pain. It works by binding to mu-opioid receptors in the brain and inhibiting the reuptake of serotonin and norepinephrine, providing a dual mechanism of pain relief. It is often prescribed when non-opioid painkillers are insufficient.